PCPs are the first line of diagnosis and treatment for most adult ADHD patients, yet are poorly educated about the disorder due to the lack of an evidence-based infrastructure for disseminating relevant information. The main reason for this problem is the lingering effects of former controversies about the disorder. According to our needs assessments, PCPs have little training about how to diagnose and treat adult ADHD. They know little about the comparative effectiveness and cost-effectiveness of the diagnostic and treatment options for this disorder. Despite this lack of knowledge, PCPs are usually the first clinicians to be in contact with ADHD adults. Because adult ADHD has a high prevalence, there are not enough psychiatrists to treat this disorder. Our research shows that many PCPs do not feel competent to diagnose adult ADHD and harbor misconceptions about the disorder that lead to erroneous clinical decisions. To disseminate information to PCPs about adult ADHD, we propose to create an innovative, online program to disseminate principles for the evidenced-based, diagnosis and treatment of ADHD in adults to PCPs. The main features of the proposed work are: 1) it will address the diagnosis and treatment of adult ADHD and its co morbidities; 2) its content will be selected and approved by clinical and academic experts; 3) it will use novel, internet based methods; 4) it will be scalable to a allow an unlimited number of participants; 5) it will include an integrated evaluation component and 5) through industry funding, advertisements, and membership fees it will be sustainable after the funding period ends. Considering our investigators, consultants and Stakeholder Advisory Board, our team comprises psychology, psychiatry, primary care medicine, nursing and also the ADHD patient community through the participation of CHADD, an ADHD patient and family support group. This will allow us to develop a high quality program that meets the needs of our target audience and, ultimately, the patients they treat.